This project involves a comparative investigation of dental implant systems which are representative of currently used implants. The study uses an in vivo dog model which permits macroscopic and, microscopic evaluations of the oral tissue (bone, connective tissue and epithelium) responses to endosteal dental implants at longitudinal time periods. This current study is attempting to elucidate, with correlative high voltage electron microscopy (HVEM) and conventional electron microscopy (TEM), the morphology of the bone-dental implant interface.